def f(k):
	r = 0
	while k > 0:
		r += k
		k -= 1
	return r
	
print f(3)
print f(4)
print f(5)
print f(10)
print f(100)

print "---"

lim = 101
step = 0
l = 0
r = 0
while step < lim:
	r += step
	print " +", step, "=", r*2
	step += 1
